$OpenBSD: patch-man_Makefile_in,v 1.2 2015/12/02 14:33:06 sthen Exp $
--- man/Makefile.in.orig	Tue Dec  1 22:29:37 2015
+++ man/Makefile.in	Wed Dec  2 14:17:20 2015
@@ -894,7 +894,7 @@ uninstall-man: uninstall-man3 uninstall-man5 uninstall
 
 
 $(MANS_CPP): $(MANS_CPP:%=%.pre)
-	$(CPP) -nostdinc -w -C -P -I$(top_srcdir)/man $@.pre  $@
+	$(CPP) -nostdinc -w -C -P -I$(top_srcdir)/man < $@.pre > $@
 
 # Tell versions [3.59,3.63) of GNU make to not export all variables.
 # Otherwise a system limit (for SysV at least) may be exceeded.
